Manganese is a type of metal found in air, soil, food, and drinking water. It is also commonly found in the well water around the world. It is washed into the drinking water from the rain plus the surface water that seeps into the ground.
While in small amounts, manganese holds no harm to human health. Yet, several research shows too much dose can be a health risk.
Indeed, the manganese in the water can be a nuisance. It produces a metallic aftertaste on the water. It stains the clothes. It clogs the valve and produces a crusty sheen on the surface of the water.
Due to the stains, bad taste, and general nuisance of manganese in the water, the federal government created a standard. It was discussed in the Safe Drinking Water Act of 1974.
There is good news. Various water treatment options can enable the water to become safe for drinking. As such, you don’t have to live your life drinking contaminated water.
Thus, this article aims to introduce ways the remove manganese from the water. Also, this would tackle the drinking water standards and the authorities' initiatives to protect its citizens.
What is Manganese?
Manganese (Mn) is a natural element found anywhere in the air, soil, and water. It is an essential nutrient for humans and animals. Yet, deficiency or overexposure to manganese can have adverse health effects.
The main exposure of manganese to humans is from food ingestion. How this happens is because manganese activates many cellular enzymes and others. Although at low dosage it is an essential nutrient, chronic exposure to high dosage may be harmful. Some data show that inhalation of manganese may affect both humans and animals. On the one hand, little data show the toxic effects of manganese through oral exposure.
The Environmental Protection Agency (EPA) provided health advisory to communities. This is a guide on the concentration for avoiding health and organoleptic problems. It provided an analysis of the current health hazard and organoleptic information for Mn-contaminated water.
Manganese Uses
Manganese has many industrial uses. They are present in making iron and steel alloys, manganese compounds, and They are also an ingredient in various products. Manganese with other compounds is present in batteries, glass, varnish, various cleaning supplies, fertilizers, fungicides, cosmetics, and livestock feeding supplements.
Manganese greensands are useful in some locations for potable water treatment. Other manganese compounds are useful for an octane-enhancing agent in unleaded petrol, like in Canada.
Sources of Manganese
Manganese makes up 0.1% of the earth’s crust, making it one of the most abundant metals on the earth’s surface. There is no manganese in pure (elemental) form but a component of over 100 minerals.
The natural sources of manganese can be found in the deep wells where they have contact with rocks for a long period. In areas of coal mining, this metal seeps through the deep mining surfaces. The manganese often occurs together with iron in the groundwater. However, manganese may occur in much lower concentrations versus iron.
Manganese is indeed present in the drinking water of most modern homes nowadays. It can give a strong metallic taste to the water and cause staining in the clothes. The water that comes from the springs and wells with high manganese levels can initially appear colorless. However, as the water is exposed to oxygen, it can go orange-brown or black.
Finally, manganese can appear commonly in western and northern countries. A study conducted by the Pennsylvania State University discovered excessive manganese concentrations for about 17% of water supplies throughout the state.
Environmental Sources and Human Exposure
Air
The levels of manganese in the air alter depending on the proximity of point sources. They reach in the ferroalloy production facilities, power plants, and coke ovens. The average level of manganese in ambient air near industrial sources is 220 to 300 ng/m3. In urban and rural areas without point sources, it was m 10 to 70 ng/m3 as reported. The U.S. EPA estimated 40 ng Mn/m3 as an average annual background concentration in urban areas based on 102 U.S. cities.
Water
Manganese springs out naturally in a lot of surface water and groundwater sources. It also erodes in soils and these waters. But there is a sad truth. Many human activities are responsible for the manganese contamination in water in some areas.
Several evidence has shown the presence of this element in many water sources. In Montreal, Canada, snow samples showed manganese concentration near an urban expressway. There are also ambient manganese concentrations in seawater reported to range from 0.4 to 10 µg/l. The levels in the freshwater range from 1 to 200 µg/l. A river water survey found dissolved manganese levels ranging from <11 to >51 µg/l.
Fortunately, there are fewer or reduced levels found in groundwater and some lakes. But, high levels were found in reservoirs. The National Water-Quality Assessment Program data show manganese is higher in surface waters (in sediments and tissues of aquatic biota) than in groundwaters (in soil and rocks).
Soil
As a naturally occurring element, manganese is present in nearly all soils—natural levels of manganese range from less than 2 to 7,000 ppm. The estimated arithmetic mean concentration is 550 ppm. Manganese accumulates in the subsoil instead of on the soil surface. Solid fraction associates an estimated 60-90% of soil manganese. There are no published reports of manganese soil ingestion.
Food
The foods we eat contain manganese. They are present in nuts, grains, fruits, leafy vegetables, legumes, tea, infant formulas, and fish and meat. Food is the most important source of manganese exposure in the general population.
Experts suggest a daily intake of 3.5 to 7 mg of manganese per day for adults. Heavy tea drinkers have a higher manganese intake. However, dietary fiber, oxalic acids, tannins, and phytic acids tend to decrease manganese absorption. The IOM set a tolerable upper intake of 11 mg/day for adults. There is insufficient data to set tolerable upper intakes for infants or children.
Standards of Drinking Water
The presence of manganese in drinking water is not a major health concern. Yet, it is recommended for secondary drinking water standards. It can cause health problems that can make the water unsuitable for home use. This is due to its bitter metallic taste, making it unpleasant to drink for humans and animals.
Manganese can lead to the browning of the laundry sinks. Also, it can result in solid or dense black stains.
It is advised that the drinking water must have manganese of no less than 0.05 mg/L. Take note that the private water systems that cater to individual households are not under the auspices of federal or state drinking water standards. Thus, the standards can only provide guidelines for the proper management of these types of water supplies.
Manganese In Drinking Water
Manganese intake from drinking is lower than the intake of food. The intake of manganese would be 20µg/day for an adult, assuming a daily water intake of 2 liters. Drinking mineral water can increase manganese dosage.
Health Effects of Manganese Overexposure
Humans consume manganese through food and drinking water. Showering and bathing with manganese-containing water do not increase your exposure since it does not penetrate the skin or even get into the air.
High exposure to manganese has been associated with toxicity to the nervous system. Drinking water with high levels of manganese is harmful to infants and young children. It may harm their brain development. According to Health Canada, manganese is commonly absorbed in the body through drinking water.
Manganese is unlikely to have toxicity effects such as cancer or reproductive damage. Young children appear to absorb more manganese than the older age groups. They also tend to excrete it less than adults. This makes it important for pregnant women and children to have clean drinking water.
Testing for Manganese
You can suspect your water if it has an orange-brown stain and a bitter and metallic taste. Only then can you easily identify the presence of manganese in your home. However, before you treat the issue, it is best to have the water tested first. With this, you can know the amount, concentration, and kinds of chemicals from out of this metal.
Meanwhile, there are two types of metals inside the home water. These are known as oxidized and reduced.
Water with reduced manganese will look clear initially. But over time, it will form into solid particles that will look black or orange-brown. On the other hand, water with oxidized manganese will have visible solid particles drawn from the well.
How to Know the Presence of Manganese in Drinking Water
Water that contains manganese often looks purple, dark brown, or blackish color. It may stain laundry and fixtures. The only way to know if you have high levels of manganese is to test your water.
Large public water suppliers or well owners are responsible for testing for potential contaminants. They monitor for contaminants, including manganese. Your water supplier will know if manganese levels are too high for humans to drink and tell you if this is the case.
You can test your drinking water for manganese. Contact your local health authority or a laboratory accredited for water contaminants in your water. You may also test your private well.
What To Do If There is Manganese in Drinking Water
Suppose you notice a discoloration in your water and ask for information on the cause. Manganese can cause discolored water. Yet, some concentrations are still safe to drink. As a precaution, don’t use discolored water to prepare food or infant formula. You should wait for confirmation that your drinking water is safe.
Other chemicals can cause discoloration in the waters, such as the iron found under similar conditions such as manganese. Handwashing, showering, or bathing with high levels of manganese don’t have known health concerns.
Know when your water or water sources exceed the safe level of manganese. If this happens, choose bottled water for infants and young children.
How to Remove Manganese From Drinking Water
Water treatment technologies have shown how to remove manganese from drinking water in your home. This action includes water softening, distillation, filtration, and reverse osmosis.
These treatment systems can be installed at the point of entry into the home. They can also be used at the point of use, such as taps or faucets. Boiling water is not suggested since it can increase manganese concentration.
Drinking water treatment products can remove manganese through independent testing and certification. Factors that influence treatment choice include hardness, iron, alkalinity, sulfide, ammonia, and dissolved organic carbon concentrations.
Product certification can provide an additional level of assurance to consumers. Product certification for products can remove manganese down to 0.5 mg/L 0.5 mg/L is available for cation exchange, distillation, filtration, and reverse osmosis.
Water Treatment Options
As soon as you have tested your water, you can determine what kind of manganese is in the water supply. Then, you’ll be able to narrow down the treatment options suitable inside your home.
Indeed, manganese can be effectively removed with the use of various treatment options. This depends on the concentration and the form of the metals.
The presence of manganese is a type of aesthetic problem. Therefore, it can potentially affect all users of the water. As such, it can be removed through the use of Point-of-Entry (POE) treatment devices.
Oxidation filtration
The oxidation filtration can inject oxygen into the water so it can remove the impurities found in it.
Indeed, this technique can remove iron in the water. However, it will require additional chemical treatment. This is chlorine bleach to eliminate the manganese.
Multiple treatment processes may apply to your issues. Make sure that your canvas and compare the units and prices among various brands. See to it that you understand the maintenance requirements for every unit. Also, have a written warranty for the device before buying.
Water Softener
The water softener is commonly used to treat hard water. However, it can also get rid of the small amounts of manganese and iron.
This method features the use of an ion-exchange process. Here sodium replaces manganese and calcium.
Manganese and iron removal also use the exchanging of manganese and iron with sodium. After that, the back-washing process can remove the metals from the softening filtering resin.
The removal efficiencies of the water softeners vary depending on the pH level, iron concentration, and water hardness. In general, water softeners are recommended when the pH level of the water is more than 6.7, the hardness is around 3 to 20 grains per gallon (50-350 mg/L), and the dissolved iron concentration is less than five mg/L.
The oxidized manganese and iron forms will produce a foul smell to the softener resin. The raw water should not come in contact with any oxidizing agents. These agents are chlorine or even the air before it enters into the softener.
It is not advised to use the softener resin bed as a mechanical filter for the oxidized manganese and iron. With this, it can cause damage to the resin bed and even need more back-washing. If oxidized manganese and iron are available in the water, then one should opt for filtration for its removal.
Point-of-use Reverse Osmosis
Meanwhile, the point-of-use reverse osmosis treats the water at an individual tap. This is where the cooking and other domestic activities’ water are drawn.
This filter uses a membrane to get rid of the unwanted molecules from the water. This enables the passage of the purified water on the other side.
Indeed, this method is easy to install, and it is common nowadays. However, the drawback can be it uses a lot of water. But for homeowners who wanted to remove manganese from the drinking water, this can be the best option.
Polyphosphate Addition
Household water containing iron concentrations of less than two mg/L can be treated with polyphosphate addition. The phosphate addition can be less effective in the treatment of manganese.
Phosphate will be fed into the water using a chemical feed pump that often requires trial and error when it comes to the dose adjustments.
In such an example, iron can be surrounded by phosphate. It cannot be eliminated from the water.
However, there are some consequences to this process. The iron will not lead to stains. But it can nevertheless produce a metallic aftertaste.
Furthermore, if there is too much phosphate added to the water, it can produce a slippery liquid. This causes diarrhea. Also, polyphosphate, when degraded in a water heater, can result in the release of a sequestered iron.
Oxidizing Filters
The oxidizing filters can both filter and oxidize the manganese that can be found in one unit. Usually, the filter uses manganese-treated greensand. However, there can also be other materials used, such as the brim.
In the manganese greensand filter, the filter media is made of potassium permanganate. It forms a coating that oxidizes the dissolved manganese and removes them from the water. The powerful combination of filtration and oxidation can effectively treat raw water with dissolved and oxidized manganese.
The manganese greens and filter will need substantial maintenance. This includes regular regeneration with the use of a potassium permanganate solution. It will be consumed during the oxidation of the metals dissolved.
Furthermore, these units will allow frequent back-washing to remove the oxidized manganese particles. Take note that the potassium permanganate solution which is used for regeneration is toxic. As such, proper handling is necessary with the use of specific safety measures.
When maintained properly, the manganese greensand filters can work best for moderate levels of both oxidized and dissolved manganese. Both are advised whenever the manganese and iron concentration is around 3 to 10 mg/L. However, bear in mind that maintenance, such as regeneration and backwashing, will increase directly with the increase of the concentration of metals.
Meanwhile, brim filters are just like manganese greensand filters. However, they do not need regeneration; they use the oxygen found in the raw water in the oxidation of the metals. As such, the raw water must contain dissolved oxygen, and the pH level should be at least 7.5 for the removal of manganese.
There are certain ideal conditions for efficient manganese removal. It is highly variable with the brim filters. The brim filters do not need any back-washing in the elimination of the accumulated oxidized particles of metals.
Oxidation Followed by Filtration
The levels of the combined manganese and iron may exceed ten mg/L. This one actual treatment will involve oxidation plus filtration.
A process like this features an added chemical to convert any dissolved manganese and iron into oxidized and solid forms. As such, this can be easily filtered out of the water.
Chlorine is one of the most used oxidants. Although, potassium permanganate and hydrogen peroxide can also be used.
A small chemical feed pump can push the chlorine (or sodium hypochlorite) solution in the water upstream. This comes from a coil of plastic pipe or mixing tank. The pipe coil or the mixing tank needs to provide contact time for the manganese and iron precipitates to form.
Also, it may need to install an activated carbon filter to remove the foul taste and odor of the residual chlorine. Chlorine is not the advised oxidant for high manganese levels. It will have a very high pH level to oxidize the manganese completely.
With these units, one needs to perform significant system maintenance regularly. As such, the solution tanks must be filled from time to time. Also, the mechanical filters need back-washing to eliminate the manganese particles accumulated.
If a carbon filter is installed, the carbon needs replacement from time to time because it will become exhausted. The type of maintenance required is determined by the metal concentration in the raw water plus the amount of water utilized.
Berkey Water Filter System
The Berkey water filter system has been proved and tested to remove heavy metal contaminants such as aluminum, arsenic, lead, iron, and manganese. According to the laboratory test, the Berkey products can remove greater than 99.9% of the manganese.
The innovative products of the Berkey filtration systems are available in 7 various models and sizes. The systems are all identical, apart from their maximum filtration rate plus storage capacity. However, they all feature the use of the same filters.
Some of the large-size products of the Berkey are the Imperial Berkey Water Filter and the Crown Berkey Water Filter.
Imperial Berkey Water Filter
The Imperial Berkey Water Filter can remove hundreds of contaminants, parasites, and bacteria in the water. Examples of heavy metals that can be eliminated are mercury, VOCs, benzene, and manganese.
This system features 2 Black Berkey purification elements, but it can be upgraded into 4 or 6. Also, this can be used by small to mid to large-sized families.
With the 4.5 gallons storage capacity, surely no one will go thirsty inside the home. Thus, grab yours nowhere!
Crown Berkey Water Filter
The Crown Berkey model is the largest type of unit from the company. It can provide clean drinking water to a large number of people, up to 150. Indeed, this can be used at the hospital, churches, orphanages, and other outdoor activities.
With this, surely, no kid, elderly, or sickly will ever have to drink dirty water again. Thus, grab yours nowhere!
Conclusion
While various treatment devices can reduce the manganese and iron from the water, some options must not be overlooked.
The alternative water sources should be investing in water treatment options just like what the Berkey Water Filters offer to its customers.
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